Scientists Tap Fungus to Protect Corn

A benign fungus that lives inside corn may yield new clues to
protecting the crop from contamination by the molds Aspergillus flavus
and Fusarium verticillioides, according to
Agricultural Research Service (ARS)
microbiologist
Don
Wicklow.

Besides causing diseases in the corn crop, the molds can contaminate
it with natural carcinogens called mycotoxins that can be harmful to both
humans and livestock. Mycotoxin-related losses, such as devalued markets,
rejected harvests and testing fees, cost the U.S. corn industry hundreds of
millions of dollars annually.

According to Wicklow, A. zeaesproduction of
pyrrocidines challenges decades-old scientific thinking that the endophyte is
an inert player in the world of corn-fungal interactions, neither harming nor
benefiting its host. Now, it appears the endophyte pays for its
room and board in corn by fending off the molds. The finding warrants taking a
closer look at the field conditions under which this rivalry occurs and
exploiting it, perhaps using cultural methods that favor the endophyte. Further
research may reveal another possible approach: inoculating corn seed with the
endophyte as a kind of living barrier against A. flavus and F.
verticillioides.

So far, Wicklow and Gloer have isolated the pyrrocidines from 13
different cultures of the endophyte. Wicklow also conducted field studies to
make sure their lab-based observations of A. zeae's antifungal activity
werent the result of a natural corn defense or the byproduct of human
error. According to Wicklow, at the ARS centers
Mycotoxin
Research Unit, the pyrrocidines also stymie certain bacteria, and are the
first-known natural products to be isolated from the endophyte.

Read more
about the research in the December issue of Agricultural Research magazine.